Questioner initially rather near riot got roughed up (12)
I believe the answer is:
interrogator
'questioner' is the definition.
(I know that interrogator is a type of questioner)
'initially rather near riot got roughed up' is the wordplay.
'initially' indicates taking the first letters.
'roughed up' indicates anagramming the letters.
The first letter of 'rather' is 'r'.
'r'+'near'+'riot'+'got'='rnearriotgot'
'rnearriotgot' anagrammed gives 'INTERROGATOR'.
(Other definitions for interrogator that I've seen before include "one grills" , "Inquisitor" , "Questioner" , "Cross-examiner" .)